(1) Field of the Invention
The present invention relates to an electric vacuum cleaner, more particularly to a suction nozzle for sucking dusts/dirts to collect them into a vacuum cleaner main body.
(2) Description of Prior Arts
Conventionally, as disclosed in Japanese Patent Publication Hei 5 No. 38609, a suction nozzle in use for an electric vacuum cleaner has a nozzle body 1 comprising an upper casing 2, lower casing 3 and a lid 4, a driving pipe 5 disposed at a rear portion of the nozzle body so as to be free to rotate and move up and down, and a suction pipe 6 connected to an end of the driving pipe 5 so as to be free to rotate and move left and right as shown in FIG. 1.
The lower casing 3 has a bottom surface for acting as a sled for a carpet. The lower casing 3 has a dust inlet 7 formed in a rectangle with more width than depth and is provided with front and rear wheels 8 and 9. The front and rear wheels 8 and 9 make a predetermined space between the lower casing 3 and the floor.
The nozzle body 1 has a brush chamber 11 having a rotary brush 10 rotatably disposed therein through a supporting shaft, and a communicating path 12 connecting the brush chamber 11 with the driving pipe 5. A dust suction path 13 is formed from the dust inlet 7 to the suction pipe 6. A drive motor 14 is disposed outside of the dust suction path 13 to rotate the rotary brush 10 through the belt 15. A bumper 16 for absorbing an impact against an obstacle is disposed between the upper casing 2 and the lower casing 3.
The rotary brush 10 is made from foaming resin and provided with a cleaning member 10a formed in a helical projection projected from the surface thereof. The rotary brush 10 is removable by taking the lid 4 off. The cleaning member 10a effectively scrapes dusts from a floor such as a carpet and the like by the rotation of the rotary brush 10 to introduce the dusts from the dust inlet 7 to the communicating path 12 by the suction force produced by an electric blower (not shown) of the cleaner main body to then collect the dusts into the cleaner main body through the suction pipe 6.
Flexible members 17 and 18 are disposed along the whole width of the dust inlet 7 about front and rear thereof. The flexible members 17 and 18 increase the suction force by improving the sealing performance between the dust inlet 7 and the floor. The flexible member 17 in front of the dust inlet 7 is removably mounted in a groove 19 formed in a front wall 1a of the nozzle body 1 by means such as a clip (not shown) and the like. The bumper 16 is disposed above the flexible member 17.
Japanese Patent Publication Sho 64 No. 6774 discloses a suction nozzle without a rotary brush, provided with a projection member 22 being movable up and down for closing a dust inlet 21 of a nozzle body 20. In this suction nozzle, the suction force thereof is increased by improving its sealing performance between the dust inlet 21 and the floor by the projection member 22. As a driving pipe 23 is positioned in a predetermined position, the projection member 22 is pushed up to open the front of the dust inlet 21. The projection member 22 is connected to the driving pipe 23 through a connecting plate 24 so that the connecting plate 24 pushes the projection member 22 upward by moving the driving pipe 23 downward. As there is any large-size solid dust, the projection member 22 is pushed upward to open the front of the dust inlet 21 to suck the dust.
In the suction nozzle as shown in FIG. 1, the flexible members 17 and 18 bend toward the dust inlet 7 by the suction force from the cleaner main body to suck dusts from spaces between them and the floor which are produced by the bendings. At a corner such as an edge of wall, the bumper 16 comes in contact with the wall surface and the flexible member 17 in front of the dust inlet is pushed toward the dust inlet 7 by a convex portion 16a disposed on the bumper 16 to increase the bending amount of the flexible member 17.
Though such large-size dusts such as a grain of rice, crumbs, a peanut and the like can be sucked by the space between the flexible member 17 and the floor, extremely large-size dusts such as tissues are swept forward by the flexible member 17 projecting downward so that the dusts are sucked at the verge of wall with the bumper 16 being in contact with the wall. Therefore it is difficult to suck such extremely large-size dusts into the nozzle body 1.
Each bending amounts of the flexible members 17 and 18 is changeable according to the suction force from the cleaner main body. Therefore, when there is a large-size solid dust regardless of the amount of dusts on the floor, the number of revolution of the electric blower should be increased and its operation is troublesome. The suction nozzle further has a problem that the noise of suction becomes louder.
In the suction nozzle as shown in FIG. 2, for sucking an extremely large-size dust, it is necessary to move the driving pipe 23 downward every time. That is, the user must take another action besides the normal operation for sucking dusts (moving the suction nozzle back and forth) so that the cleaning is troublesome working. The structure of the nozzle body 20 is complex so as to increase the number of parts so that the product cost is risen.
With regard to both sides of the nozzle body 1 in the width direction, the nozzle body 1 usually has cutouts (not shown) formed in side walls on the both sides thereof for a typical vacuum cleaner so as to suck dusts at a verge of wall. According to this structure, it is capable of sucking dusts at a verge of wall or a corner of a room. However, since air is always leaking from such a cutout, it is not suitable for dusts in a thick-piled carpet, in a deep groove or the like.
On the other hand, as the cutouts is closed for reducing the air leakage, the suction power of the nozzle body 1 to the floor becomes too strong for a high power type vacuum cleaner in recent years. Therefore, it is hard to operate it.